Stalin was casual, Hitler was calculated. Certainly, Stalin was brutal, but the Ukrainian Famine was from Collectivisation. All food was stored centrally, with no means of redistributing it.
He saw the Ukrainians as dangerous and rebellious and didn't give a shit about them starving.
In Kazakhstan, they collectivised the animals of the nomadic population. They had thousands of years of herding them in different seasonal pastures, but the Soviets decided that everyone should have an equal number, the animals starved and so did the people.
The Kazaks lived on dairy, horse and mutton, with the better of villagers hosting regular feasts, people stuffed their clothes with leftover meat. (There was no agriculture to speak of). At least 8 million people starved to death, there are no accurate figures.
Currently 16 million, it's thought that the population is still lower than it was in the 20s.
My wife's maternal grandmother was the 13th of 15 children, the first 12 died, during Collectivisation. And these weren't even State Enemies, they embraced Communism happily.
Things were different after the war, when many Kazakhs became "subversive."